Adriano in Siria is one of several of Metastasio’s opera seria libretti which were used by more than 60 composers, in this case from the first setting in 1732 by Caldara, to the last by Mercadante in 1828; earlier this year, a recording of Veracini’s 1735 version was released, and J.C. Bach’s 1765 version was staged in London. Adriano ends with a gesture of imperial magnanimity; hence many of the new versions were composed for royal occasions across Europe, such as Pergolesi’s setting, performed in Naples in October 1734, which was dedicated to Charles Bourbon, Duke of Parma and future king of Spain, whose forces had captured the kingdom of Sicily and its capital Naples the previous May.

Compared to Vinci, Hasse, Porpora, et alia, Pergolesi hasn’t featured as prominently in the recent wave of opera seria revivals and aria recordings. There is however a complete edition of his operas on DVD, recorded at the 2010 Pergolesi tercentenary festival in his native Jesi, and from that set Adriano in Siria is also available as a stand-alone and on YouTube.

This performance was organised by Opera Settecento, a group dedicated to reviving under-performed opera seria and whose chairman Christopher Silvester is a particular fan of this opera. Their previous events were Vivaldi’s Griselda in 2014 and Handel’s Catone in Utica in 2015 at the London Handel Festival; plans for 2016 include a return to the Handel Festival in March and another September Cadogan Hall performance of an opera by Hasse.

The action of Adriano takes place in Antioch, where the future Roman emperor Hadrian as local governor has conquered and offered peace to the Parthians. He seeks an affair with Emirena, the daughter of the Parthian king Osroa. She is betrothed to Farnaspe, a Parthian prince. Hadrian’s friend Aquilo is in love with Hadrian’s betrothed, Sabina. The plot centres on Osroa’s attempts for revenge against Hadrian, who in turn is persuaded by Sabina to pardon everyone and marry her.

Despite its general appeal, the music is variable: Act 1 drags (no fault of the excellent young cast or the orchestra) until the final two arias, Act 2 is the best balanced musically and dramatically, and the final act wraps things up with rather too much action and too little music. The concert-format (chairs and music stands for the singers, in front of the orchestra) didn’t hinder the dramatic involvement of the cast, who stayed in role and responded subtly to the unfolding of events.

In the title role, Michael Taylor immediately established the authority and confidence of the victorious governor, with a full tone and legato maintained with careful use of limited vibrato. The high-lying coloratura was all managed with ease, and the voice balanced from top to bottom, only very occasionally thinning under pressure of the passagework. Russian mezzo Maria Ostroukhova (oddly identified as soprano in the programme booklet) produced a warm and rich sound, conveying the emotional torment of Emirena and unafraid to use the heavy voice to push fearlessly through the fast passages with mostly clear articulation. Her impassioned Act 1 aria Sola mi lasci a piangere was the first musical highlight of the evening.

Following on rapidly, Farnaspe’s aria Lieto così talvolta is the most performed and recorded extract from the whole opera. Pergolesi sensibly placed this aria at the end of the act – despite being less bravura than other arias for the character and in the opera, it’s the undoubted musical standout in the work. The obbligato oboe, representing a caged nightingale, was sensitively controlled and with some genuine quiet playing. The role was originally written for Caffarelli, and all the arias were handled impeccably by Erica Eloff who maintained a clear, bright tone across the huge range required, and showed first-rate technical control in runs over the break and back.

Augusta Hebbert showed similar control in the role of Sabina, including a perfectly floated held note in Chi soffre, senza pianto, though the emotion was a little generalised through all her arias. The incidental role of Aquilo was reduced further by the last-minute cut of the character’s Act 2 aria, leaving just the one Act 3 aria Contento forse vivere – with music familiar in Stravinsky’s borrowing for Pulcinella. Cenk Karaferya’s full vibrato did justice to the character’s frustrated passion for Sabina.

The most sensational singing of the evening came from the tenor Gyula Rab, who is only in the second year of his professional career. Urged on by the full orchestral sound in his bravura arias, he conveyed Osroa’s desire for revenge with an impassioned, slightly Italianate sound at the top, firm tone and precision in the fast detail.

Leo Duarte, busy these days as principle oboe with the English Baroque Soloists in Orphée et Eurydice, was making his operatic conducting debut this evening. The intention was clearly to keep the drama flowing, the next recitative typically pushing ahead immediately after the last beat of the preceding aria, though inevitably some clapping intruded as the audience wished to show genuine appreciation for the singers. The ensemble and tempi benefitted especially from Jonathan Rees’ excellent cello continuo. It’s a long evening for the violins, and although in a few places better attention to articulation and variety of tone would have kept the textures more interesting, the tuning and pace was secure throughout.

In passing, it should be mentioned that the programme booklets for the concert were delayed, only arriving during the first interval, and the £5 charge was generously waived as an apology – although, as both a thorough proofread and a pruning of self-indulgent biographies were still needed, paying would have rankled.